Current Sensors How to select a good one or roll your own.

Electric Motors and Controllers
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Arlo1
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Re: Current Sensors How to select a good one or roll your own.

Post by Arlo1 » Dec 21, 2017 11:07 am

marcos wrote:
Dec 21, 2017 6:34 am
Great to hear. 6 days ago I gently reminded Isabellenhuete about the shunt samples I asked for and after some checking they told me they will ship around christmas (ship to argentina). I'm not building pcbs until have samples in my hand.

The samples I asked for are 2000A shunts that are not actually available for ordering because they are sold with the electronics built in. The little board I made is for a commercial, ready to order shunt (that I think I'm not getting a sample of).
I'll get you in contact with the factory to get you some BAS-Z-R000035 shunts.
OK cool. Thanks for all of that. If I need I can run 2 in parallel.
The first few tests will be dyno time with this new inverter.
that will be much more stress on the system then in a drag application.
I checked out there company last night and the video is pretty awesome even though I don't speak German it gets you pumped up.
My Leaf motor controller build. viewtopic.php?f=30&t=63982&p=963227#p963227
My YSR build http://www.youtube.com/watch?v=BRo8r5g4NBg
RC and most types of Lithium batteries you MUST know your individual cell voltages charging and discharging.
Don't keep them were you cant afford smoke or fire!
Never above 4.2v never below 2.7v EVER!!!
HI power controller design. Game Changer
http://www.undergroundelectrics.ca/

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Arlo1
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Re: Current Sensors How to select a good one or roll your own.

Post by Arlo1 » Jan 04, 2018 2:05 am

Damn no word on any shunts. I have just started searching but I am not sure what I need. I can work the math but what type of design for a shunt resistor is a good one?
My Leaf motor controller build. viewtopic.php?f=30&t=63982&p=963227#p963227
My YSR build http://www.youtube.com/watch?v=BRo8r5g4NBg
RC and most types of Lithium batteries you MUST know your individual cell voltages charging and discharging.
Don't keep them were you cant afford smoke or fire!
Never above 4.2v never below 2.7v EVER!!!
HI power controller design. Game Changer
http://www.undergroundelectrics.ca/

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fechter
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Re: Current Sensors How to select a good one or roll your own.

Post by fechter » Jan 04, 2018 9:12 am

Do you have a size constraint? I've seen plenty of them for industrial use, but they're huge. It may be possible to harvest the resistance elements from some (Manganin?) and repackage to fit the space.

Most of the higher rated ones use multiple parallel resistance elements, either flat or round.
600A shunt.jpg
600A shunt.jpg (109.66 KiB) Viewed 255 times
400A shunt 1.jpg
400A shunt 1.jpg (16.91 KiB) Viewed 255 times
"One test is worth a thousand opinions"

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Arlo1
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Re: Current Sensors How to select a good one or roll your ow

Post by Arlo1 » Feb 12, 2018 1:07 am

marcos wrote:
Aug 15, 2017 4:58 pm
The board is here
https://github.com/paltatech/current_sensor

This is the bom generated by kicad
https://github.com/paltatech/current_se ... x?raw=true

I didn't bother to fill the passives part#, I copied the filter from the other forum and those values or even the opamp could change.

Something worth asking is how to solder the shunt to the pcb. If 170°C is the max temp, how do you do a 250°C reflow?
Whats J3 for? Nightly builds messed up the SCH on me :(

:Edit it looks like it's for powering the unit.
My Leaf motor controller build. viewtopic.php?f=30&t=63982&p=963227#p963227
My YSR build http://www.youtube.com/watch?v=BRo8r5g4NBg
RC and most types of Lithium batteries you MUST know your individual cell voltages charging and discharging.
Don't keep them were you cant afford smoke or fire!
Never above 4.2v never below 2.7v EVER!!!
HI power controller design. Game Changer
http://www.undergroundelectrics.ca/

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marcos
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Re: Current Sensors How to select a good one or roll your own.

Post by marcos » Feb 12, 2018 6:18 pm

J3 connector has 5v power input, Signal output (0A=2.5v), and GND.
top level.png
(22.02 KiB) Not downloaded yet
Image

I'm not mentally prepared yet to upgrade to the latest kicad nighties because of the new library remapping. Will have to do sooner than later, but I know it will be painful...

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Arlo1
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Re: Current Sensors How to select a good one or roll your own.

Post by Arlo1 » Feb 12, 2018 7:15 pm

marcos wrote:
Feb 12, 2018 6:18 pm
J3 connector has 5v power input, Signal output (0A=2.5v), and GND.

top level.png

Image

So... I think J3 is on the wrong board...

Sorry Marcos
My bad I was thinking the board with the screw holes was to be bolted to a shunt.

Its the other way around. Now I get it.
Thanks.

-Arlin
My Leaf motor controller build. viewtopic.php?f=30&t=63982&p=963227#p963227
My YSR build http://www.youtube.com/watch?v=BRo8r5g4NBg
RC and most types of Lithium batteries you MUST know your individual cell voltages charging and discharging.
Don't keep them were you cant afford smoke or fire!
Never above 4.2v never below 2.7v EVER!!!
HI power controller design. Game Changer
http://www.undergroundelectrics.ca/

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